samples/rpmsg/rpmsg_client_sample.c

   1 /*
   2  * Remote processor messaging - sample client driver
   3  *
   4  * Copyright (C) 2011 Texas Instruments, Inc.
   5  * Copyright (C) 2011 Google, Inc.
   6  *
   7  * Ohad Ben-Cohen <ohad@wizery.com>
   8  * Brian Swetland <swetland@google.com>
   9  *
  10  * This software is licensed under the terms of the GNU General Public
  11  * License version 2, as published by the Free Software Foundation, and
  12  * may be copied, distributed, and modified under those terms.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/rpmsg.h>
  23
  24 #define MSG             "hello world!"
  25 #define MSG_LIMIT       100
  26
  27 static void rpmsg_sample_cb(struct rpmsg_channel *rpdev, void *data, int len,
  28                                                 void *priv, u32 src)
  29 {
  30         int ret;
  31         static int rx_count;
  32
  33         dev_info(&rpdev->dev, "incoming msg %d (src: 0x%x)\n", ++rx_count, src);
  34
  35         print_hex_dump(KERN_DEBUG, __func__, DUMP_PREFIX_NONE, 16, 1,
  36                        data, len,  true);
  37
  38         /* samples should not live forever */
  39         if (rx_count >= MSG_LIMIT) {
  40                 dev_info(&rpdev->dev, "goodbye!\n");
  41                 return;
  42         }
  43
  44         /* send a new message now */
  45         ret = rpmsg_send(rpdev, MSG, strlen(MSG));
  46         if (ret)
  47                 dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
  48 }
  49
  50 static int rpmsg_sample_probe(struct rpmsg_channel *rpdev)
  51 {
  52         int ret;
  53
  54         dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n",
  55                                         rpdev->src, rpdev->dst);
  56
  57         /* send a message to our remote processor */
  58         ret = rpmsg_send(rpdev, MSG, strlen(MSG));
  59         if (ret) {
  60                 dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
  61                 return ret;
  62         }
  63
  64         return 0;
  65 }
  66
  67 static void rpmsg_sample_remove(struct rpmsg_channel *rpdev)
  68 {
  69         dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n");
  70 }
  71
  72 static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = {
  73         { .name = "rpmsg-client-sample" },
  74         { },
  75 };
  76 MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);
  77
  78 static struct rpmsg_driver rpmsg_sample_client = {
  79         .drv.name       = KBUILD_MODNAME,
  80         .drv.owner      = THIS_MODULE,
  81         .id_table       = rpmsg_driver_sample_id_table,
  82         .probe          = rpmsg_sample_probe,
  83         .callback       = rpmsg_sample_cb,
  84         .remove         = rpmsg_sample_remove,
  85 };
  86
  87 static int __init rpmsg_client_sample_init(void)
  88 {
  89         return register_rpmsg_driver(&rpmsg_sample_client);
  90 }
  91 module_init(rpmsg_client_sample_init);
  92
  93 static void __exit rpmsg_client_sample_fini(void)
  94 {
  95         unregister_rpmsg_driver(&rpmsg_sample_client);
  96 }
  97 module_exit(rpmsg_client_sample_fini);
  98
  99 MODULE_DESCRIPTION("Remote processor messaging sample client driver");
 100 MODULE_LICENSE("GPL v2");